A stick shift handle for an automatic transmission permits a driver to change the gears of a vehicle transmission by moving the stick shift handle between various positions. Typically, the stick shift handle is locked in a particular gear position until unlocked by the driver. The driver unlocks the stick shift handle by pressing a release button either at the front of the stick shift handle or on its side, which, in turn, causes an actuator in the stick shift handle to release the stick shift handle from a shift lock mechanism.
Problems may arise with the actuator that unlocks the stick shift handle. Specifically, the stick shift handle, which houses the actuator, is generally made from plastic and fiberglass. This material has a high coefficient of friction and causes the actuator to experience a fair amount of friction when moved. While manufacturers have sought to overcome this problem by placing lubricant between the actuator and the stick shift handle, during frequent use, the lubricant tends to migrate from the area of contact between the actuator and the stick shift handle.
In addition, for a side actuating stick shift handle, manufacturers have sought to reduce the effort of unlocking the stick shift handle by employing a cam as an actuator. To unlock the stick shift handle, the driver presses a release button, which causes pivotal movement of the cam. The cam then moves an unlocking member along a linear path. However, the pivoting action of the cam tends to force the unlocking member to move in a pivoting fashion as well. On occasion, this type of movement may cause a backlash through the release button. Manufacturers have sought to eliminate this problem by creating a notch in the cam to prevent the unlocking member from moving radially relatively to the cam. This fix is time consuming to implement.
A need therefore exists for a stick shift handle assembly that provides smooth and inexpensive actuation of a shift lock mechanism.